Homogeneous phenotype of the gypsy limb-girdle MD with the gamma-sarcoglycan C283Y mutation.

Objective: To characterize the clinical phenotype of LGMD2C in gypsies.
Background: Limb-girdle muscular dystrophy (LGMD) in gypsies of Western Europe is caused by a homozygous C283Y mutation on the same haplotype, suggesting a founder effect.
Methods: We performed clinical, laboratory, and muscle imaging studies of 40 patients.
Results: Mean age at onset was 5.3 years. One half of the patients had loss of ambulation by the age of 12; 13% still could walk after age 16. Calf hypertrophy, scapular winging, macroglossia, and lumbar hyperlordosis were common. Girdle, trunk, and proximal limb flexor muscles had earlier and more severe involvement. Cardiomyopathy was not observed. Five patients in the third decade of life required mechanical ventilation. Scoliosis was common in the nonambulatory stage.
Conclusions: LGMD2C in gypsy patients with C283Y mutation presents a rather homogeneous phenotype, characterized by an initial Duchenne-like progressive course followed by a more prolonged survival rate possibly due to the absence of early respiratory impairment and cardiac failure.